Hopper bottom furnace



April 4, 1950 J. A. BALMER HOPPER BOTTOM FURNACE 2 Sheets-Sheet 1 Filed Oct. 27, 1945 Elm/ovum JAMES A. B/ILMf/i Patented Apr. 4, 1950 um'rso s TAT 2,503,148 HOPPER iso r'roiu fiifit'iidn "Jaiiies A. Balmelr, Worcester, lt l asszpassi "for Riley "Stoker Corporation,- orcester,

corporation of Massachusetts "lipplication october'27, is isjseiieiivc. 'c' iiei 1 This invention relates to hopper bottom furnaces, and more particularly to furnace bottoms of the type comprising metal tubes through which water is circulated to-c'ool the tubes and generate steam.

Hopper bottom furnaces as ordinarily construc'ted include two bottom walls which slope downwardly from the front and rear respectively toward an 'a'sh discharge slot located beneath thec entral portion of the furnace. A separate set of water tubes is associated with each of these walls. Anash hopperis installed beneath the "discharge slot tofre'ceive ashes which'fall therethrough, and this-hopper is 'p'rovided with doors -to permit periodic dumping of the accumulat'ed "ashes "into a sluicew'ay "or other ashconveying apparatus. These-prior furnaces are very expensive and they occupy a considerable amount of valuable space. i Separate headers are required to supply waterto the lower ends of the two sets of water tubes and both of these headers must be suitably connectedto the boiler to receive water therefrom. The ash hopperis .a bulky and costly device, and it adds greatly to the basement headroom required. U

' It is accordingly the main object of the in- Claims. (01. 1 22:4235) vention to provide a water cooled-hopper bottom furnace which will'be comparatively inexpensive to manufacture; and which will require considerably less space than prior constructions. 7

"It is a further object of the invention to providea relatively simple and inexpensive water cooled furnace bottom in which ashes may be allowed to accumulate. andfrom which the accumulated ashes may be freely discharged by gravity at intervals.

With these and other objects'in view,as will be apparent to those skilled in the art, the invention resides in'the combination of parts set forth in the specification and covered by the claims appended hereto. i

'lieferring to the drawing illustratingone emjddlment ofuthe invention, and in which like reference numerals indicate like parts, v H

Fig. 1' is' a longitudin 1 section through a water cooled furnace bottom, taken on the line l-l of Fig. 3;

Fig. 2 is a section taken on the line 2-2 of v Fig. 1; and

the line 3-3 of 2 fi liii sf i ishL"I1 ii i r m fuel be im edes-m known tamer rbr b e nmsu sse sib hin the armies in. m omher ms ere-is-l'ocateda"traris= 7 s4 H *a-po'rtibnof a steamonersickness-construction. v The bottom of the furnace I0 is hoseda provide a hopper withinwhich ashesmay 'be allowed to accumulate and from which they may be freely discharged by gravity. -For this purpose a wall l3" slopes downwardlyand-forwe rd y. rb i i e r wal 1 std aii i T slopes downwardly and rearwardly from theffro'nt wall 'I l These converging {walls ineet beneaththe center of the furnace'toprovide a V -sliape d hopp'er'bottom, the walls being so steep throughout that the hopper is self-discharging by gravity; To insure such self-discharge of the ashes, each 0f h ls e d2 p fe rab sli e an angle or more thanforty-five degrees. illustrated, both wens have fsubstantially the same inclination. Adjacent the jimctionof the two inclined 'walls thefront wall 20 is provided slidable in the plane of the wall Zlland arranged to be actuated by any "suitable operating mechanism 24. Beneath each opening 2| and connected thereto is a funnel shaped dust-tight casing or chute 25 leading downwardly to a suitable ash'conveyor, such as asluiceipipe 26.

The I two inclined hopper bottom walls are protected from excessiveheat by means of water tubes adapted to serve as steam generating elements. As shown, arow of water tubes 28 is associated with the rear bottom wall l9, and a row of water tubes 29 is associated with the front bottom wall 20. Preferably the rear tubes 28 are: closely spaced, whereas the front tubes 29 are more widely space'd and 'bent laterally to avoidinter'feren'ce withth'e'"ash 'discharge open-' ings 2|, as best shown in Fig. 3. The lower ends of the tubes 28 and 29 are connected to a common transverse horizontal header 3| which is supplied with water from the'drum It by means of a row of downcomer tubes 32 located beneath the tubes 28. The header 3| is located adjacent to the junction of the two walls 19 and 20, and it is supported by means of coil springs 34. The tubes 28 and 29 extend upwardly along the furnace walls l2 and II respectively, and they are suitably connected at their upper ends in known manner to the steam boiler to provide a complete path for the circulation of water through the tubes.

In the operation of the invention the closely spaced water tubes 28 will protect the walls 12 and I9, which are exposed to intense radiant heat, and the more widely spaced water tubes 29 will protect the walls II and 20, which are exposed to radiant heat of somewhat less intensity. The ash resulting from the combustion of the pulverized fuel will fall on the walls 19 and 20, sliding down these walls by gravity and collecting directly above the doors 23. When these doors are opened by sliding them upwardly the accumulated ashes will drop through the openings 2| into the casings and the sluice pipe 26. Thus the discharge of ashes will take place by gravity alone, no hoeing or raking being required, and since the casings 25 are attached to the wall 20 around the openings 2| there will be no escape of dust into the room. The furnace bottom itself forms a hopper in which the ash may accumulate, no additional ash hopper being required. Consequently the cost of the apparatus and the space required are greatly decreased.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A hopper bottom furnace comprising two oppositely disposed inclined walls which converge and meet beneath the central portion of the furnace to form a V-shaped hopper bottom within which ashes may be allowed to accumulate, the walls being sufficiently steep to ensure selfdischarge of ashes therefrom by gravity, one of said walls having an ash discharge opening therethrough adjacent the junction of the walls, a door to close the opening, a horizontal header adjacent the junction of the walls, and two separate rows of water tubes extending upwardly from the header and along the respective inclined walls, the tubes adjacent the opening being spaced apart to allow ashes to pass through the opening under the influence of gravity when the door is opened.

2. A hopper bottom furnace comprising two oppositely disposed inclined walls which converge and meet beneaththe central portion of the furnace to form a v-shaped hopper bottom within which ashes may be allowed to accumulate, the walls being sufiiciently steep to ensure self-discharge of ashes therefrom by gravity, one of said walls having an ash discharge opening therethrough adjacent the junction of the walls, a door to close the opening, an ash conveyor beneath the opening, a dust-tight casing connecting the opening with the ash conveyor, a horizontal header adjacent the junction of the walls, and two separate rows of water tubes extending upwardly from the header and along the respective inclined walls, the tubes adjacent the opening being spaced apart to allow ashes to pass through the opening under the influence of gravity when the door is opened.

1 the opening, a horizontal header adjacent the junction of the walls, a row of relatively closely spaced water tubes extending upwardly from the header and along the rear wall, and a row of relatively Widely spaced water tubes extending upwardly from the header and along the front wall, the last-mentioned tubes being bent laterally to avoid interference with the opening.

4. A hopper bottom furnace comprising two oppositely disposed inclined walls which converge and meet beneath the central portion of the furnace to form a V-shaped hopper bottom within which ashes may be allowed to accumulate, the walls being suificiently steep to ensure self-dis: charge of ashes therefrom by gravity, one of said walls having an ash discharge opening there through adjacent the junction of the walls, a door to close the opening and slidable upwardly in the plane of the corresponding ,wall to permit the discharge of ashes through the opening by gravity, an ash conveyor beneath the opening, a dust-tight casing comiectingthe opening with the ash conveyor, a horizontal header adjacent the junction of the walls, and two separate rows of water tubes extending upwardly from the header and along the respective inclined walls, the tubes adjacent the opening being spaced apart to allow ashes to pass through the opening under the influence of gravity when the door is opened. I

5. A hopper bottom furnace comprising two oppositely disposed inclined walls which converge and meet beneath the central portion of the furnace to form a V-shaped hopper bottom Within which ashes may be allowed to accumulate, the walls being sufficiently steep to ensure self-discharge of ashes-therefrom by gravity, one of the walls having an ash discharge opening there-- through adjacent the junction of the walls, a door toclose the opening, and water tubes ex-; tending along the said wallsand so disposed as to allow ashes to pass through the opening under the influence of gravity when the door is opened.

JAMES A. BALMER. REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS vVan Brunt et al. May 20, 1941 

